Flux CD is a tool that enables teams to manage controlled deployments and rollbacks of their applications in Kubernetes clusters using GitOps principles. To set up Flux CD, you need to install the Flux CLI, create a GitHub repository, and configure your Kubernetes cluster to synchronize with the repository. Once set up, Flux CD can be used to perform rollouts and rollbacks by updating the image version in your Kustomize configuration and pushing the changes to your Git repository. Flux CD also supports advanced rollout strategies through integration with Flagger, which provides automated canary deployments, A/B testing, and blue/green deployments. With Flux CD, teams can confidently manage application updates and rollbacks, ensuring that their applications are stable and meet the desired state defined in their manifests.